William p



(No Model.)

W. P. GIBSON.

AUTOMATIC STOP MECHANISM FOR ELEVATOR$. No. 412,328. Patented Oct. 8,1889.

Nv PETERS. Hwmumew hu. Washington, 11. C.

UNITED STATES PATENT Erica:

\VILLIAM P. GIBSON, OF NEW YORK, N. Y.

SPECIFICATION forming part of Letters Patent N 0. 412,328, dated October8, 1889. Application filed December 31, 1888. Serial No. 294,997. (Nomodel.)

To all whom it may concern:

Be it known that 1, WILLIAM P. GIBSON, a citizen of the United States,residing at New York, county of New York, and State of New York, haveinvented certain new and useful Improvements in Automatic StopMechanisms for Elevators, fully described and represented in thefollowing specification and the accompanying drawings, forming a part ofthe same.

This invention relates to improvements in safety stop mechanisms forelevators for antomatically arresting the elevator-oar at its upper orlower limit of movement when, through carelessness or from any othercause,

he elevator-conductor has failed to manipulate the hand-rope or otherconnection to properly operate the valve or other stopping mechanism ofthe elevator to cause the movement of the car to be arrested at thesepoints.

It is the object of the present invention to provide a stop mechanism ofthis character of such construction that its operations will be certain,reliable, and effective, which shall be capable of adjustment, so as tobe rendered operative within any desired distance of the limit ofmovement of the elevator-car, and which shall accomplish the arrest ofthe car at its upper or lower limit of movement easily, gradually, andwithout sudden jar.

To this end the invention consists, briefly, in providing the shaftcarrying the sheave of the hoistingcable of the elevator-car throughouta port-ion of its length with screw-threads, at each end of whichscrewthreaded portion of said shaft is mounted a stationary nut, formingan abutment, with which engages at the proper time during the movementof the elevatorcar a traveling nut, also mounted upon said shaft betweensaid stationary nuts, and connected to a barrel loosely mounted uponsaid shaft and connected to a sheave, also loose upon the shaft andinclosing said screw-threaded portion of said shaft. Around the sheavethus connected to the barrel there passes a rope, which may be theordinary hand rope, and which is connected to the valve or otherstopping and starting mechanism. in such manner as to stop the car atthe top and loottom of the shaft, according to the direction in whichthe rope is moved. The several devices are so constructed and arrangedand so timed in their operations that during the greater part of theupward or downward movement of the elevator-car they will remaininoperative, so as not to interfere with the movement of the car; butwhen the elevator-car has come within a certain distance of its limit ofmovement in either direction, the traveling nut connected to the barrelwill engage with one or the other of the stationary nuts upon the shaft,and communicate the rotary movement of said shaft to said barrel andalso to the sheave of the rope, and thus cause said rope to travel inthe direction of the cars movement, and this movementwill continue untilthe rope has operated the valve or other mechanism of the elevator tostop the car.

For the purposes of adjustment, so as to render the mechanism operativewithin desired distances of the limits of movement of the elevator-car,the stationary nuts upon the screw-threaded shaft are provided withlocknuts, hereinafter referred to, by which, when said stationary nutshave been adjusted to desired positions, they may be locked therein andprevented from movement.

As the construction and operation of the stop mechanism constituting thepresent invention can be best understood from an illustration and adetailed description of an organization embodying the same, all furtherpreliminary description will be omitted and such detailed description begiven in connection with the accompanying drawings, in which isillustrated so much of the mechanism of an ordinary elevator as isnecessary for an understanding of the invention, and in which- Figure lis a front elevation of an elevator'car, its hoisting-cable, andvalve-operating hand-rope and their sheaves and connections. Fig. 2 is alongitudinal section, upon an enlarged scale, of the stop mechanism ofthe present invention; and Fig. 3 is a crosssection of the same, takenon the line 3 of Fig. 2.

Referring to Fig. 1, it will be understood that A represents anelevator-car of the ordinary form, connected to the upper side of whichis the usual hoisting-cable 13, passing over a sheave C at the top ofthe elevator shaft. The sheave G is fast upon a shaft D,

journaled in suitable bearings at the top of the elevator-shaft. Theshaft D has also mounted loosely upon it a second sheave E, around whichpasses a rope F. This rope B may be the ordinary hand-rope forcontrolling the elevator, as illustrated in the present case; or wherethe valve or other stopping and startingmechanism is operated from thecar by other connections than a rope this rope F may be provided inaddition to such connections, and may pass through or outside the car.The hand-rope, as shown in the present case, passes through theelevator-car in convenient position to be grasped by the hand of theconductor, as shown by dotted lines in Fig. 1, and also passes over aguide-pulley a and thence downward to the connections for operating thestopping and starting mechanism, to which it is connected in the usualmanner. The sheave E forms one end of abarrel H, inclosing a portion ofthe shaft D. That portion of the shaft D inclosed within the barrel H isscrew-threaded and carries at or near each end stationary nuts 9 h.Between the nuts 9 and h the shaft D has loosely mounted upon it atravcling nut i, capable of movement during the rotation of said shaftalong the same between the nuts 9 and h, as hereinafter described. Thetraveling nut 71 is provided with a projecting end j, which enters andfits loosely,

, within a longitudinal recess 70, formed in the barrel H. During therotation of the shaft D'the traveling nut 'iwill, by reason of itsconnection with the loosely-mounted barrel H in the manner described,travel along said shaft toward one or the other of the nuts 9 h,according to the direction of movement of the car, with which nut itwill engage when the car reaches the limit of its movement. In order toprovide for the ready engagement of the traveling nut 2' with the nuts gh, each of said nuts is provided upon its engagingsurface withoppositely-arrauged shoulders Z, as best shown in Fig. 2. The nuts 9 andh are in addition provided with lock-n uts 'm, by which they aresecurely locked and held in position upon the shaft D.

Theoperation of the mechanism which has been described is as follows:Let it be assumed that the carA is in the position shown in Fig. 1 andis moving upward. As the upward movement of the car continues the shaftD Will be revolved and with it the nuts 9 and h, the loosely-mountedbarrel H remaining stationary and the traveling nutil traveling alongthe shaft D toward the nutg, being guided in this movement by itsconnection with the barrel H. NVhen the nut t' has reached the nut g, itwill engage therewith. When the nuts 2' and g are thus brought intoengagement, the nuti will be caused to revolve with the shaft D and willcommunicate the rotary movement of said shaft to the barrel H and sheaveE, said sheave revolving in the same direction as the shaft D anddrawing upward upon the handrope F. This revolution of the sheave E willcontinue until it has drawn upward suf ficiently upon the hand-rope F tostop the car. The operation of the different parts of the stop mechanismis so timed that the movement of the car will be arrested in an easy andgradual manner and free from jar and within the limit of its upwardmovement. When the car is descending, the op oration will be reversed,the nut 71 during the rotation of the shaft D in the opposite directiontraveling along said shaft and engaging with the nut h at its oppositeend. When the nuts '5 and h are thus brought into engagement, the sheave.E will then revolve in a direction contrary to that just described andmove the hand-rope F downward to stop the car.

The nuts g and it may be adjusted alongthe shaft D at any desireddistance from each other and be locked in their positions by theirlock-nuts m.

The abutments for the nutz' will preferably be formed by nuts g h, asshown; but where adjustment is not required the abutments may be fixedupon the shaft D, or the abutments may be either fixed or adjustableupon the barrel.

When the car has been stopped at the limit of its movement in eitherdirection, the rope F may be moved in the same direction. to start thecar, as such movement, instead of drawing the nut 1' against thestationary nut, will turn the nut 71 so as to back it away from thestationary nut.

Vvhat I claim is 1. The combination, with an elevator-car, itshoisting-cable, and the sheave over which said cable passes at the topof the shaft, of a threaded shaft 1), provided with abutments and fixedto said sheave, a sheave E and barrel H, turning freely upon said shaft,a traveling nut 7;, working upon said threaded shaft between theabutmeuts and connected to said barrel to lock it and the sheave E tothe shaft when it engages with either abut-' ment, and a stopping-ropeF, passing around said sheave E, substantially as described.

2. The combination, with an elevator-car, its hoisting-cable, and thesheave over which said cable passes at the top of the shaft, of athreaded shaft D, fixed to said sheave, a sheave E and barrel H, turningfreely upon said shaft, a traveling nut 2', working upon said threadedshaft between adjustable abut-.

ments and connected to said barrel to lock it and the sheave E to theshaft when it engages with either abutmeut, and a stoppingrope F,passing around said sheave E, substantially as described.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses.

WM. P. GIBSON.

Witnesses:

J. J. KENNEDY, EDWARD WooD.

